US4943373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilic porous membrane of polyvinylidene fluoride and method for production thereof
Assignee: Terumo Corp
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Filing: 1988-01-11
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Granted: 1990-07-24
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Expires: 2008-01-11
Abstract
Abstract A hydrophilic porous membrane of polyvinylidene fluoride excelling in perviousness to water and other various properties and enjoying high commercial value, having uniform hydropilicity imparted to the surface of pores therein, which porous membrane is characterized by the fact that the reflection spectrum thereof in the visible zone is substantially unchanged from that which existed before the treatment for impartation of hydrophilicity. A method for the production of the hydrophilic porous membrane, characterized by chemically treating the porous membrane in a strong alkali solution containing an oxidizing agent.
Inventors
- 👤 Makoto Onishi
- 👤 Yukio Seita
- 👤 Noriyuki Koyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:18
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D69/00; B01D69/02; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/34; C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08K; C08K3/00; C08K3/10; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/16; Y; Y10; Y10S; Y10S521/00; Y10S521/918
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
49 words
A hydrophilic porous membrane of polyvinylidene fluoride having uniform hydrophilicity imparted to the surface of pores therein, which porous membrane is characterized by the fact that the reflection spectrum thereof in the visible zone is substantially unchanged from that which existed before the treatment for impartation of said hydrophilicity.
Claim 2
Dependent Claim
49 words
A hydrophilic porous membrane of polyvinylidene fluoride having uniform hydrophilicity imparted to the surface of pores therein, which porous membrane is characterized by the fact that the reflection spectrum thereof in the visible zone is substantially unchanged from that which existed before the treatment for impartation of said hydrophilicity.
Claim 3
Dependent Claim
77 words
A hydrophilic porous membrane of polyvinylidene fluoride according to claim 1, wherein said impartation of uniform hydrophilicity to the surface of pores therein is effected by introducing a polar group on the molecule of polyvinylidene fluoride through a chemical treatment with an oxidizing agent and said porous membrane is characterized by the fact that the reflection spectrum thereof in the visible zone is substantially unchanged from that which existed before the treatment for impartation of said hydrophilicity.
Claim 4
Dependent Claim
33 words
A hydrophilic porous membrane of polyvinylidene fluoride according to claim 1 or claim 2, wherein said membrane, in a dry state, assumes a white color or no color as viewed with human eyes.
References Cited (Backward Citations)
JPS5225781A
Cited
JPS53110680A
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JPS5616187A
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JPS5618333A
Cited
GB2058802A
Cited
JPS5893734A
Cited
JPS62267340A
Cited
US4774132A
Cited
US4810384A
Cited
US4851121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-23 | 1994-01-22 | 1994-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-23 | 1998-01-22 | 1998-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-23 | 2002-01-22 | 2002-07-24 | $7700.00 | Window Closed / Lapsed |